Giant Hydatid Cyst with Diaphragmatic, Pericardial, and Hepatic Involvement: Use of Extracorporeal Circulation for Major Liver Resection: A Case Report and Literature Review

Background

Echinococcosis, also known as hydatid disease, is a zoonosis caused by Echinococcus granulosus taeniasis, a parasite with a wide geographical distribution, with endemic areas in Central America, South America, and some Mediterranean regions.

Echinococcus granulosus is 1 of the 6 species of the parasite described in the literature, of which only 4 cause disease in humans. Its main hosts are dogs, wolves, and coyotes. Transmission to humans occurs via the fecal-oral route through contact with infected animals or by consuming contaminated food. Once in the body, the parasite accumulates in the main organs, forming cysts; these spherical structures have slow but variable growth, ranging from 1 to 3 cm in diameter per year [1]. For this reason, the clinical presentation of the disease is mostly asymptomatic. Symptoms are secondary to the stage of the disease and to the compressive effect caused by the progressive growth of the cyst. Other symptoms derive from complications, where the inherent risk is septic shock secondary to intraperitoneal rupture of the cyst, which increases the risk of mortality due to massive dissemination.

The aim of this article is to present the clinical case of a giant hydatid cyst with diaphragmatic, pericardial, hepatic, and retrohepatic vena cava involvement that required surgical re-section under extracorporeal circulation, achieving total radical resection.

Case Report

A 32-year-old man from Caruru, Vaupés, Colombia was referred to the emergency department from the medical center in Mitú due to 2 months of mass-like sensation in the right rib cage, associated with feverish peaks and abdominal pain in the right upper quadrant. At the medical center, a mass was documented in the lower region of the right hemithorax with evidence of a liver lesion in radiologic findings. A puncture was performed for drainage and the patient was referred to our medical center.

On admission, the patient was asymptomatic. His vital signs were within normal ranges, and the only positive finding on physical examination was a purulent discharge in the anterior thorax at the puncture site. The patient with no relevant medical history, but had multiple risk factors of exposure to echinococcus: he was from a rural area, had frequent consumption of water from unknown sources, with exposure to dogs, and ingestion of guagua (an animal that is an intermediate host of echinococcus, and the main source in Colombia). Given the symptomatology, a thoracoabdominal CT scan was requested, with the finding of a mass in the lower lobe anterior segment of the right lung, hypodense, multiseptate of 71×68 mm associated with increased volume of the left hepatic lobe with focal lesions, hypodense multiseptated with a transverse diameter of 152 mm, and subphrenic extension (Figure 1A, 1B).

Due to high suspicion of echinococcus infection, anthelmintic treatment with Albendazole 400 mg orally twice a day was started and, due to clinical signs of superinfection, targeted antibiotic treatment was started. Magnetic resonance imaging (MRI) of the brain was performed due to high risk of dissemination without pathological findings and, given the lack of clarity in images of hepatic parenchymal involvement, a contrast MRI of the abdomen was requested, which showed a multiloculated cystic mass hyperintense in T2, hypointense in T1, that involved hepatic parenchyma (segments I, II, IV), subphrenic space, and right hemidiaphragm with dimensions of 50×106×171 mm. Also, at the base of the right hemithorax there was an image of similar characteristics of 48×76×71 mm and another in hepatic segment II of approximately 8 mm (Figure 2A, 2B). These findings were consistent with cystic echinococcosis (CE) 2–3A stages according to the World Health Organization classification for hydatid cyst [2].

The case was presented to a multidisciplinary surgical board between hepatobiliary and thoracic surgery, and a surgical approach was decided. During this first surgical procedure, a right posterolateral thoracotomy was performed at the level of the sixth intercostal arch, and a 7×7 cm hydatid cyst was identified adhered to the right lower pulmonary lobe and to the ipsilateral hemidiaphragm (Figure 3), abundant purulent collection in the wall including costal cartilage of the 6th, 7th, and 8th right costal arch (Figure 4), and non-anatomic resection of the right lower lobe was performed including the cystic lesion. The incision was extended to thoraco-phreno laparotomy and resection of the compromised costal cartilage was performed. Visualization of the pericardium and diaphragm showed multiple secondary cystic seeding. A partial portion of the diaphragm was resected with joint extraction of the pulmonary segment previously dissected. (Figure 5). After that, hepatic release was attempted, but the patient became unstable because of distributive-vasogenic shock. The procedure stopped and a ViaFlex bag was placed and fixed separating the thoracic and abdominal cavity, closed thoracostomy was placed for bilateral drainage, and the total surgical time was approximately 7 hours, with a total blood loss of 600 cc. The patient was transferred to the ICU under invasive mechanical ventilation, multiple vasopressors with immediate post-operative blood transfusion requirement, renal replacement therapy for 24 hours due to refractory metabolic acidosis, and liver dys-function that did not progress to liver failure. Given the high suspicion of anaphylactic inflammatory response mediated by cytokines in response to the dissemination of the microorganism, antibiotic management was stepped up.

Once the patient reached hemodynamic stability, he underwent a second surgery 8 days after the first intervention. Given the high risk of bleeding and vasogenic shock due to pericar-dial seeding and infiltration of the retrohepatic vena cava, extracorporeal circulation assistance was indicated and the Cell Saver system was available if required.

Right femoral artery and vein cannulation was performed, positioning in the superior vena cava to start extracorporeal support. Initially, partial pericardiectomy plus cyst resection was done with pericardial reconstruction with a synthetic patch anchored to pericardial remnants with 5-0 Prolene (Figure 6). Subsequently, through a previous thoraco-phreno laparotomy incision, release of the hepatic cyst from the retrohepatic vena cava was achieved and left hepatectomy was performed (Figure 7) with bipolar energy. A 30×45 mm Parietene mesh was fixed with polypropylene to each end of the right and left diaphragmatic remnant and to the anterior thoracic wall (Figure 8).

The procedure was without complications, with a surgical time of 6 hours and total blood loss of 350 cc. The patient returned to spontaneous circulation with a total cardiopulmonary bypass time of 80 minutes. Due to the risk of parasitic dissemination, the blood filtered by the Cell Saver device was not returned to spontaneous circulation. The Pringle maneuver was not performed in any of the surgical interventions. Hypertonic solution was used in both surgeries to continuously irrigate the cavity to avoid dissemination of the parasite and to keep the resected cysts and tissues in order to ensure clean and radical resection of the infected tissue.

The patient was transferred to the ICU with evolution without complications. After recovery with the support of physical therapy, respiratory therapy, nutrition, and pain clinic, the patient was transferred to general hospitalization, where he was subsequently discharged home with anthelmintic therapy with Albendazole 400 mg orally twice a day for 90 days. Ambulatory follow-up was performed by treating specialties. Tissue biopsy confirmed infection with Echinococcus granulosus. After 30, 60, and 90 days, no relapse or complications had occurred.

Discussion

The first description of hydatid liver disease was given in the time of Hippocrates and was known as “the liver full of water” [3]. It was predominant in rural areas and was associated with places where sheep grazing and hunting were common. Hydatid disease, or echinococcosis, is a zoonosis caused by Echinococcus taeniasis, a parasite of which 6 species have been described in literature, but only 4 cause human infections.

Echinococcus granulosus is the main organism responsible for the cystic presentation in hydatid disease [1]. It has a wide geographic distribution, with endemic areas in Central America, South America, and some Mediterranean regions, affecting mainly men [4–6]. Other subtypes, such as Echinococcus multilocularis, are responsible for alveolar presentation, and Echinococcus vigeli and Echinococcus oligarthrus are responsible for polycystic presentation. These last 3 have a comparatively diffuse geographic distribution given their low incidence [7].

The main host of echinococcus are dogs, wolves, and coyotes; however, animals such as sheep and pigs act as intermediate vectors. In humans, transmission is via the fecal-oral route. Once in contact with the gastrointestinal system, the parasite in the larval stage migrates and penetrates the intestinal lamina propria, gaining access to lymphatic vessels and bloodstream, especially the mesenteric circulation, achieving hematogenous dissemination.

The main organs involved are the liver and lung. The liver, given its irrigation and drainage dependent on mesenteric vessels, is the main reservoir. In the literature, liver involvement is reported in approximately 70–75% of cases, followed by pulmonary involvement in 15–25% of cases [1,6]. About two-thirds of the reported cases had a single cyst, with multiorgan involvement being very rare [6]. In the tissue, the larva promotes formation of cysts with 3 layers [1,8,9]. The outermost layer, called the pericyst, represents the reactive inflammation of the host tissue to the parasite, creating a fibrous layer. The middle layer, called the ectocyst, is an acellular intermediate membrane. The inner layer, called the endocyst, is the only vital portion of the structure; it contains the epithelial germinal layer and is in contact with the parasite. Given its vitality, it can create septa and internal membranes. The growth of the cysts is slow, at approximately 1 cm during the first 6 months [1,8]. Later, the growth depends on the resistance of the host tissues, and if the internal hydrostatic pressure exceeds the resistance of the pericyst, there may be spontaneous rupture.

Because of its slow growth, the disease is usually asymptomatic. Symptomatology of an intact cyst is due to compression or mass effect, which occasionally produces cyst growth; however, it is common that the symptomatology is secondary to complications such as rupture or superinfection. There is a wide range of signs and symptoms, most of them non-specific, such as fever, diaphoresis, and weight loss. Some are closely related to the location and number of cysts and others to the size, indicating disease progression. In cases where there is hepatic involvement, the main symptom is abdominal pain [3,8]. There may be a sensation of mass, hepatomegaly, signs of portal hypertension, or obstructive biliary syndromes related to cholangitis, and in some cases, symptoms derived from the formation of subphrenic abscesses or broncho-biliary fistulas [1]. If there is pulmonary involvement, symptoms such as dyspnea and chest pain are the main manifestations [1,10].

Generally, the diagnosis is made in advanced stages of the disease, mainly by incidental imaging findings. The main guiding tool is ultrasound, which is accessible, economical, and useful in identifying the number, size, location, dimension, and vitality of cysts, with a sensitivity of 95% [6,11]. However, it is not easy to differentiate between hydatid cyst and other space-occupying lesions such as tumors or abscesses of diverse etiology, so tools such as tomography can be used, or in special cases that require better characterization, magnetic resonance can be used [1,12].

As mentioned, hepatopulmonary involvement is predominant in this disease. Imaging findings reported indicate that in liver cysts predominate in the right hepatic lobe in about 71% of cases [5]. Additionally, in cases with pulmonary involvement, whether primary or secondary, the disease predominates in the right lung, with the lower lobe frequently being the most affected. Other tissues involved include serosal surfaces, kidneys, and spleen in less than 0.5% of cases [1,6].

The indicated management depends on the extent of the disease and the size of the cyst. The approach aims to eliminate the parasite from the body and prevent recurrence of the disease. There are 2 pillars of approach: medical management, and invasive management with percutaneous interventions and radical open or laparoscopic surgical management [11,13]. Usually, the clinical condition improves with medical management with an anthelmintic, but in recent decades invasive management has shown better results in conjunction with administration of anthelmintic in the pre- and post-operative period. Follow-up with imaging is needed for at least 2 months after surgical management.

Hassen Gharbi, radiologist and biophysicist, described in 1981 a classification of hepatic hydatid cysts with ultrasound findings in a series of cases. Over the years, attempts have been made to standardize the invasive approach according to this classification. Five types of hepatic hydatid cysts are described, considering type I and II as uncomplicated disease susceptible to percutaneous management, and type III and IV as complicated disease that benefits from radical management [13,14].

The percutaneous approach presents a high risk of dissemination and relapse in complicated disease, making radical surgical management the first choice, as it presents less risk of recurrence and can cure the condition completely in spite of the high surgical risk of perforation and massive dissemination. Depending on the location of the cyst, cystectomy is possible; however, in cases of severe involvement, hepatectomy is recommended; the more peripheral the cyst, the lower the risk of recurrence. The intraoperative benefit of prophylactic lavage of the cavity with hypertonic saline solution has been described, reducing the risk of dissemination and relapse.

The management of this condition has to be individualized for each patient. The approach to the disease in either of these strategies have high risk of complications associated with cyst rupture, dissemination of the parasite, and massive septic-anaphylactic shock. In the case presented here, there was multi-organ compromise, which included the liver, retrohepatic vena cava, diaphragm, lungs, and pericardium; however, the surgical multidisciplinary approach given was able to not only remove the main cyst but also to prevent seeding of the disease, achieving a complete eradication of the parasite in the patient.

Regarding extracorporeal circulation assistance, the literature describes cases where it is implemented in single primary cardiac hydatid cysts. However, there is a report of 1 case in which extracorporeal circulation was required due to migration of hydatid membranes to the right atrium during surgical resection of a primary liver cyst with infiltration of the inferior vena cava. To the best of our knowledge this is the first report of extracorporeal circulation assistance for large hepatic-diaphragmatic and pericardial cyst resection.

Conclusions

Hydatid disease is a rare zoonosis endemic to rural areas, with a wide geographic distribution. Echinococcus granulosus is the main microorganism involved in the cystic presentation of the disease. Given its slow growth, it is mostly asymptomatic with late diagnosis, posing diagnostic and therapeutic medical challenges with high rates of complications and mortality.

An individualized, mixed surgical and medical approach is necessary. Depending on the number, size, and location of cysts, a multidisciplinary approach is recommended.

Extracorporeal circulation assistance is a relevant tool for achieving hemodynamic stability in patients with cardiac or great vessel involvement given the high latent risk of systemic dissemination, sepsis, and relapse. However, it is important to realize that the parasite can be disseminated through the bloodstream; therefore, the recirculation of the blood filtered in the Cell Saver is debated and the risk/benefit ratio must be taken into account. In this particular case, the blood filter was not used.